Ordinary materials transfer energy by (1) non-solar heat gain by direct conduction, convection, and radiation; (2) solar heat gain in the form of radiation; and (3) airflow from both ventilation and infiltration through the material. Common insulating materials are designed to block conductive or convective heat transfer or reflect radiant heat. Common insulating materials include: bulky fiber materials, such as fiberglass, rock and slag wool, cellulose, and natural fiber; foams and other air trapping systems; and reflective insulation systems, such as reflective foils. Bulky fiber materials insulate by resisting conductive and—to a lesser degree—convective heat flow in a cavity. Air trapping systems, such as spray foams and rigid foam boards trap air or another gas to resist conductive heat flow. Reflective insulation systems reflect radiant heat away from living spaces, making them particularly useful in warm climates, but do not insulate against cold.
Currently, a common method of insulating is using fiberglass insulation. Fiberglass has high insulating capabilities, but requires space that could otherwise be saved by using a more efficient and thinner material, decreasing the square-footage that could be utilized for other things. Additionally, fiberglass' insulating capabilities can decrease by up to 40% in low temperatures and up to 30% in high humidity environments. Furthermore, small tears greatly compromise efficiency, and any resulting moisture can cause a loss of up to 50% of its insulation capabilities. The refrigerator, an appliance that greatly depends on insulation for its function, is generally fitted with polyurethane foam as its insulator. While polyurethane foams are effective insulators and have strong structural integrity, they are not durable and gradually disintegrate, especially in hot or humid conditions. Additionally, polyurethane releases toxic fumes when burned, making it extremely environmentally unfriendly and difficult to dispose of after its inevitable deterioration. Most ordinary, non-insulating materials need costly modifications or bulky additions to insulate well.
Therefore, it would be advantageous to provide a thermally-versatile insulating film for warm, cold, and humid climates that insulates against thermal energy transfer. Furthermore, it would be advantageous to provide a flexible film that can be applied to a variety of surfaces, both planar and non-planar. Additionally, it would be advantageous to provide thermally efficient films that transmit a maximum fraction of incident visible light intensity for transparent surfaces such as windows.